fs/ext4/namei.c

   1 /*
   2  *  linux/fs/ext4/namei.c
   3  *
   4  * Copyright (C) 1992, 1993, 1994, 1995
   5  * Remy Card (card@masi.ibp.fr)
   6  * Laboratoire MASI - Institut Blaise Pascal
   7  * Universite Pierre et Marie Curie (Paris VI)
   8  *
   9  *  from
  10  *
  11  *  linux/fs/minix/namei.c
  12  *
  13  *  Copyright (C) 1991, 1992  Linus Torvalds
  14  *
  15  *  Big-endian to little-endian byte-swapping/bitmaps by
  16  *        David S. Miller (davem@caip.rutgers.edu), 1995
  17  *  Directory entry file type support and forward compatibility hooks
  18  *      for B-tree directories by Theodore Ts'o (tytso@mit.edu), 1998
  19  *  Hash Tree Directory indexing (c)
  20  *      Daniel Phillips, 2001
  21  *  Hash Tree Directory indexing porting
  22  *      Christopher Li, 2002
  23  *  Hash Tree Directory indexing cleanup
  24  *      Theodore Ts'o, 2002
  25  */
  26
  27 #include <linux/fs.h>
  28 #include <linux/pagemap.h>
  29 #include <linux/jbd2.h>
  30 #include <linux/time.h>
  31 #include <linux/fcntl.h>
  32 #include <linux/stat.h>
  33 #include <linux/string.h>
  34 #include <linux/quotaops.h>
  35 #include <linux/buffer_head.h>
  36 #include <linux/bio.h>
  37 #include "ext4.h"
  38 #include "ext4_jbd2.h"
  39
  40 #include "namei.h"
  41 #include "xattr.h"
  42 #include "acl.h"
  43
  44 /*
  45  * define how far ahead to read directories while searching them.
  46  */
  47 #define NAMEI_RA_CHUNKS  2
  48 #define NAMEI_RA_BLOCKS  4
  49 #define NAMEI_RA_SIZE        (NAMEI_RA_CHUNKS * NAMEI_RA_BLOCKS)
  50 #define NAMEI_RA_INDEX(c,b)  (((c) * NAMEI_RA_BLOCKS) + (b))
  51
  52 static struct buffer_head *ext4_append(handle_t *handle,
  53                                         struct inode *inode,
  54                                         ext4_lblk_t *block, int *err)
  55 {
  56         struct buffer_head *bh;
  57
  58         *block = inode->i_size >> inode->i_sb->s_blocksize_bits;
  59
  60         bh = ext4_bread(handle, inode, *block, 1, err);
  61         if (bh) {
  62                 inode->i_size += inode->i_sb->s_blocksize;
  63                 EXT4_I(inode)->i_disksize = inode->i_size;
  64                 *err = ext4_journal_get_write_access(handle, bh);
  65                 if (*err) {
  66                         brelse(bh);
  67                         bh = NULL;
  68                 }
  69         }
  70         return bh;
  71 }
  72
  73 #ifndef assert
  74 #define assert(test) J_ASSERT(test)
  75 #endif
  76
  77 #ifdef DX_DEBUG
  78 #define dxtrace(command) command
  79 #else
  80 #define dxtrace(command)
  81 #endif
  82
  83 struct fake_dirent
  84 {
  85         __le32 inode;
  86         __le16 rec_len;
  87         u8 name_len;
  88         u8 file_type;
  89 };
  90
  91 struct dx_countlimit
  92 {
  93         __le16 limit;
  94         __le16 count;
  95 };
  96
  97 struct dx_entry
  98 {
  99         __le32 hash;
 100         __le32 block;
 101 };
 102
 103 /*
 104  * dx_root_info is laid out so that if it should somehow get overlaid by a
 105  * dirent the two low bits of the hash version will be zero.  Therefore, the
 106  * hash version mod 4 should never be 0.  Sincerely, the paranoia department.
 107  */
 108
 109 struct dx_root
 110 {
 111         struct fake_dirent dot;
 112         char dot_name[4];
 113         struct fake_dirent dotdot;
 114         char dotdot_name[4];
 115         struct dx_root_info
 116         {
 117                 __le32 reserved_zero;
 118                 u8 hash_version;
 119                 u8 info_length; /* 8 */
 120                 u8 indirect_levels;
 121                 u8 unused_flags;
 122         }
 123         info;
 124         struct dx_entry entries[0];
 125 };
 126
 127 struct dx_node
 128 {
 129         struct fake_dirent fake;
 130         struct dx_entry entries[0];
 131 };
 132
 133
 134 struct dx_frame
 135 {
 136         struct buffer_head *bh;
 137         struct dx_entry *entries;
 138         struct dx_entry *at;
 139 };
 140
 141 struct dx_map_entry
 142 {
 143         u32 hash;
 144         u16 offs;
 145         u16 size;
 146 };
 147
 148 static inline ext4_lblk_t dx_get_block(struct dx_entry *entry);
 149 static void dx_set_block(struct dx_entry *entry, ext4_lblk_t value);
 150 static inline unsigned dx_get_hash(struct dx_entry *entry);
 151 static void dx_set_hash(struct dx_entry *entry, unsigned value);
 152 static unsigned dx_get_count(struct dx_entry *entries);
 153 static unsigned dx_get_limit(struct dx_entry *entries);
 154 static void dx_set_count(struct dx_entry *entries, unsigned value);
 155 static void dx_set_limit(struct dx_entry *entries, unsigned value);
 156 static unsigned dx_root_limit(struct inode *dir, unsigned infosize);
 157 static unsigned dx_node_limit(struct inode *dir);
 158 static struct dx_frame *dx_probe(const struct qstr *d_name,
 159                                  struct inode *dir,
 160                                  struct dx_hash_info *hinfo,
 161                                  struct dx_frame *frame,
 162                                  int *err);
 163 static void dx_release(struct dx_frame *frames);
 164 static int dx_make_map(struct ext4_dir_entry_2 *de, unsigned blocksize,
 165                        struct dx_hash_info *hinfo, struct dx_map_entry map[]);
 166 static void dx_sort_map(struct dx_map_entry *map, unsigned count);
 167 static struct ext4_dir_entry_2 *dx_move_dirents(char *from, char *to,
 168                 struct dx_map_entry *offsets, int count, unsigned blocksize);
 169 static struct ext4_dir_entry_2* dx_pack_dirents(char *base, unsigned blocksize);
 170 static void dx_insert_block(struct dx_frame *frame,
 171                                         u32 hash, ext4_lblk_t block);
 172 static int ext4_htree_next_block(struct inode *dir, __u32 hash,
 173                                  struct dx_frame *frame,
 174                                  struct dx_frame *frames,
 175                                  __u32 *start_hash);
 176 static struct buffer_head * ext4_dx_find_entry(struct inode *dir,
 177                 const struct qstr *d_name,
 178                 struct ext4_dir_entry_2 **res_dir,
 179                 int *err);
 180 static int ext4_dx_add_entry(handle_t *handle, struct dentry *dentry,
 181                              struct inode *inode);
 182
 183 unsigned int ext4_rec_len_from_disk(__le16 dlen, unsigned blocksize)
 184 {
 185         unsigned len = le16_to_cpu(dlen);
 186
 187         if (len == EXT4_MAX_REC_LEN || len == 0)
 188                 return blocksize;
 189         return (len & 65532) | ((len & 3) << 16);
 190 }
 191
 192 __le16 ext4_rec_len_to_disk(unsigned len, unsigned blocksize)
 193 {
 194         if ((len > blocksize) || (blocksize > (1 << 18)) || (len & 3))
 195                 BUG();
 196         if (len < 65536)
 197                 return cpu_to_le16(len);
 198         if (len == blocksize) {
 199                 if (blocksize == 65536)
 200                         return cpu_to_le16(EXT4_MAX_REC_LEN);
 201                 else
 202                         return cpu_to_le16(0);
 203         }
 204         return cpu_to_le16((len & 65532) | ((len >> 16) & 3));
 205 }
 206
 207 /*
 208  * p is at least 6 bytes before the end of page
 209  */
 210 static inline struct ext4_dir_entry_2 *
 211 ext4_next_entry(struct ext4_dir_entry_2 *p, unsigned long blocksize)
 212 {
 213         return (struct ext4_dir_entry_2 *)((char *)p +
 214                 ext4_rec_len_from_disk(p->rec_len, blocksize));
 215 }
 216
 217 /*
 218  * Future: use high four bits of block for coalesce-on-delete flags
 219  * Mask them off for now.
 220  */
 221
 222 static inline ext4_lblk_t dx_get_block(struct dx_entry *entry)
 223 {
 224         return le32_to_cpu(entry->block) & 0x00ffffff;
 225 }
 226
 227 static inline void dx_set_block(struct dx_entry *entry, ext4_lblk_t value)
 228 {
 229         entry->block = cpu_to_le32(value);
 230 }
 231
 232 static inline unsigned dx_get_hash(struct dx_entry *entry)
 233 {
 234         return le32_to_cpu(entry->hash);
 235 }
 236
 237 static inline void dx_set_hash(struct dx_entry *entry, unsigned value)
 238 {
 239         entry->hash = cpu_to_le32(value);
 240 }
 241
 242 static inline unsigned dx_get_count(struct dx_entry *entries)
 243 {
 244         return le16_to_cpu(((struct dx_countlimit *) entries)->count);
 245 }
 246
 247 static inline unsigned dx_get_limit(struct dx_entry *entries)
 248 {
 249         return le16_to_cpu(((struct dx_countlimit *) entries)->limit);
 250 }
 251
 252 static inline void dx_set_count(struct dx_entry *entries, unsigned value)
 253 {
 254         ((struct dx_countlimit *) entries)->count = cpu_to_le16(value);
 255 }
 256
 257 static inline void dx_set_limit(struct dx_entry *entries, unsigned value)
 258 {
 259         ((struct dx_countlimit *) entries)->limit = cpu_to_le16(value);
 260 }
 261
 262 static inline unsigned dx_root_limit(struct inode *dir, unsigned infosize)
 263 {
 264         unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(1) -
 265                 EXT4_DIR_REC_LEN(2) - infosize;
 266         return entry_space / sizeof(struct dx_entry);
 267 }
 268
 269 static inline unsigned dx_node_limit(struct inode *dir)
 270 {
 271         unsigned entry_space = dir->i_sb->s_blocksize - EXT4_DIR_REC_LEN(0);
 272         return entry_space / sizeof(struct dx_entry);
 273 }
 274
 275 /*
 276  * Debug
 277  */
 278 #ifdef DX_DEBUG
 279 static void dx_show_index(char * label, struct dx_entry *entries)
 280 {
 281         int i, n = dx_get_count (entries);
 282         printk(KERN_DEBUG "%s index ", label);
 283         for (i = 0; i < n; i++) {
 284                 printk("%x->%lu ", i ? dx_get_hash(entries + i) :
 285                                 0, (unsigned long)dx_get_block(entries + i));
 286         }
 287         printk("\n");
 288 }
 289
 290 struct stats
 291 {
 292         unsigned names;
 293         unsigned space;
 294         unsigned bcount;
 295 };
 296
 297 static struct stats dx_show_leaf(struct dx_hash_info *hinfo, struct ext4_dir_entry_2 *de,
 298                                  int size, int show_names)
 299 {
 300         unsigned names = 0, space = 0;
 301         char *base = (char *) de;
 302         struct dx_hash_info h = *hinfo;
 303
 304         printk("names: ");
 305         while ((char *) de < base + size)
 306         {
 307                 if (de->inode)
 308                 {
 309                         if (show_names)
 310                         {
 311                                 int len = de->name_len;
 312                                 char *name = de->name;
 313                                 while (len--) printk("%c", *name++);
 314                                 ext4fs_dirhash(de->name, de->name_len, &h);
 315                                 printk(":%x.%u ", h.hash,
 316                                        ((char *) de - base));
 317                         }
 318                         space += EXT4_DIR_REC_LEN(de->name_len);
 319                         names++;
 320                 }
 321                 de = ext4_next_entry(de, size);
 322         }
 323         printk("(%i)\n", names);
 324         return (struct stats) { names, space, 1 };
 325 }
 326
 327 struct stats dx_show_entries(struct dx_hash_info *hinfo, struct inode *dir,
 328                              struct dx_entry *entries, int levels)
 329 {
 330         unsigned blocksize = dir->i_sb->s_blocksize;
 331         unsigned count = dx_get_count(entries), names = 0, space = 0, i;
 332         unsigned bcount = 0;
 333         struct buffer_head *bh;
 334         int err;
 335         printk("%i indexed blocks...\n", count);
 336         for (i = 0; i < count; i++, entries++)
 337         {
 338                 ext4_lblk_t block = dx_get_block(entries);
 339                 ext4_lblk_t hash  = i ? dx_get_hash(entries): 0;
 340                 u32 range = i < count - 1? (dx_get_hash(entries + 1) - hash): ~hash;
 341                 struct stats stats;
 342                 printk("%s%3u:%03u hash %8x/%8x ",levels?"":"   ", i, block, hash, range);
 343                 if (!(bh = ext4_bread (NULL,dir, block, 0,&err))) continue;
 344                 stats = levels?
 345                    dx_show_entries(hinfo, dir, ((struct dx_node *) bh->b_data)->entries, levels - 1):
 346                    dx_show_leaf(hinfo, (struct ext4_dir_entry_2 *) bh->b_data, blocksize, 0);
 347                 names += stats.names;
 348                 space += stats.space;
 349                 bcount += stats.bcount;
 350                 brelse(bh);
 351         }
 352         if (bcount)
 353                 printk(KERN_DEBUG "%snames %u, fullness %u (%u%%)\n",
 354                        levels ? "" : "   ", names, space/bcount,
 355                        (space/bcount)*100/blocksize);
 356         return (struct stats) { names, space, bcount};
 357 }
 358 #endif /* DX_DEBUG */
 359
 360 /*
 361  * Probe for a directory leaf block to search.
 362  *
 363  * dx_probe can return ERR_BAD_DX_DIR, which means there was a format
 364  * error in the directory index, and the caller should fall back to
 365  * searching the directory normally.  The callers of dx_probe **MUST**
 366  * check for this error code, and make sure it never gets reflected
 367  * back to userspace.
 368  */
 369 static struct dx_frame *
 370 dx_probe(const struct qstr *d_name, struct inode *dir,
 371          struct dx_hash_info *hinfo, struct dx_frame *frame_in, int *err)
 372 {
 373         unsigned count, indirect;
 374         struct dx_entry *at, *entries, *p, *q, *m;
 375         struct dx_root *root;
 376         struct buffer_head *bh;
 377         struct dx_frame *frame = frame_in;
 378         u32 hash;
 379
 380         frame->bh = NULL;
 381         if (!(bh = ext4_bread (NULL,dir, 0, 0, err)))
 382                 goto fail;
 383         root = (struct dx_root *) bh->b_data;
 384         if (root->info.hash_version != DX_HASH_TEA &&
 385             root->info.hash_version != DX_HASH_HALF_MD4 &&
 386             root->info.hash_version != DX_HASH_LEGACY) {
 387                 ext4_warning(dir->i_sb, __func__,
 388                              "Unrecognised inode hash code %d",
 389                              root->info.hash_version);
 390                 brelse(bh);
 391                 *err = ERR_BAD_DX_DIR;
 392                 goto fail;
 393         }
 394         hinfo->hash_version = root->info.hash_version;
 395         if (hinfo->hash_version <= DX_HASH_TEA)
 396                 hinfo->hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
 397         hinfo->seed = EXT4_SB(dir->i_sb)->s_hash_seed;
 398         if (d_name)
 399                 ext4fs_dirhash(d_name->name, d_name->len, hinfo);
 400         hash = hinfo->hash;
 401
 402         if (root->info.unused_flags & 1) {
 403                 ext4_warning(dir->i_sb, __func__,
 404                              "Unimplemented inode hash flags: %#06x",
 405                              root->info.unused_flags);
 406                 brelse(bh);
 407                 *err = ERR_BAD_DX_DIR;
 408                 goto fail;
 409         }
 410
 411         if ((indirect = root->info.indirect_levels) > 1) {
 412                 ext4_warning(dir->i_sb, __func__,
 413                              "Unimplemented inode hash depth: %#06x",
 414                              root->info.indirect_levels);
 415                 brelse(bh);
 416                 *err = ERR_BAD_DX_DIR;
 417                 goto fail;
 418         }
 419
 420         entries = (struct dx_entry *) (((char *)&root->info) +
 421                                        root->info.info_length);
 422
 423         if (dx_get_limit(entries) != dx_root_limit(dir,
 424                                                    root->info.info_length)) {
 425                 ext4_warning(dir->i_sb, __func__,
 426                              "dx entry: limit != root limit");
 427                 brelse(bh);
 428                 *err = ERR_BAD_DX_DIR;
 429                 goto fail;
 430         }
 431
 432         dxtrace(printk("Look up %x", hash));
 433         while (1)
 434         {
 435                 count = dx_get_count(entries);
 436                 if (!count || count > dx_get_limit(entries)) {
 437                         ext4_warning(dir->i_sb, __func__,
 438                                      "dx entry: no count or count > limit");
 439                         brelse(bh);
 440                         *err = ERR_BAD_DX_DIR;
 441                         goto fail2;
 442                 }
 443
 444                 p = entries + 1;
 445                 q = entries + count - 1;
 446                 while (p <= q)
 447                 {
 448                         m = p + (q - p)/2;
 449                         dxtrace(printk("."));
 450                         if (dx_get_hash(m) > hash)
 451                                 q = m - 1;
 452                         else
 453                                 p = m + 1;
 454                 }
 455
 456                 if (0) // linear search cross check
 457                 {
 458                         unsigned n = count - 1;
 459                         at = entries;
 460                         while (n--)
 461                         {
 462                                 dxtrace(printk(","));
 463                                 if (dx_get_hash(++at) > hash)
 464                                 {
 465                                         at--;
 466                                         break;
 467                                 }
 468                         }
 469                         assert (at == p - 1);
 470                 }
 471
 472                 at = p - 1;
 473                 dxtrace(printk(" %x->%u\n", at == entries? 0: dx_get_hash(at), dx_get_block(at)));
 474                 frame->bh = bh;
 475                 frame->entries = entries;
 476                 frame->at = at;
 477                 if (!indirect--) return frame;
 478                 if (!(bh = ext4_bread (NULL,dir, dx_get_block(at), 0, err)))
 479                         goto fail2;
 480                 at = entries = ((struct dx_node *) bh->b_data)->entries;
 481                 if (dx_get_limit(entries) != dx_node_limit (dir)) {
 482                         ext4_warning(dir->i_sb, __func__,
 483                                      "dx entry: limit != node limit");
 484                         brelse(bh);
 485                         *err = ERR_BAD_DX_DIR;
 486                         goto fail2;
 487                 }
 488                 frame++;
 489                 frame->bh = NULL;
 490         }
 491 fail2:
 492         while (frame >= frame_in) {
 493                 brelse(frame->bh);
 494                 frame--;
 495         }
 496 fail:
 497         if (*err == ERR_BAD_DX_DIR)
 498                 ext4_warning(dir->i_sb, __func__,
 499                              "Corrupt dir inode %ld, running e2fsck is "
 500                              "recommended.", dir->i_ino);
 501         return NULL;
 502 }
 503
 504 static void dx_release (struct dx_frame *frames)
 505 {
 506         if (frames[0].bh == NULL)
 507                 return;
 508
 509         if (((struct dx_root *) frames[0].bh->b_data)->info.indirect_levels)
 510                 brelse(frames[1].bh);
 511         brelse(frames[0].bh);
 512 }
 513
 514 /*
 515  * This function increments the frame pointer to search the next leaf
 516  * block, and reads in the necessary intervening nodes if the search
 517  * should be necessary.  Whether or not the search is necessary is
 518  * controlled by the hash parameter.  If the hash value is even, then
 519  * the search is only continued if the next block starts with that
 520  * hash value.  This is used if we are searching for a specific file.
 521  *
 522  * If the hash value is HASH_NB_ALWAYS, then always go to the next block.
 523  *
 524  * This function returns 1 if the caller should continue to search,
 525  * or 0 if it should not.  If there is an error reading one of the
 526  * index blocks, it will a negative error code.
 527  *
 528  * If start_hash is non-null, it will be filled in with the starting
 529  * hash of the next page.
 530  */
 531 static int ext4_htree_next_block(struct inode *dir, __u32 hash,
 532                                  struct dx_frame *frame,
 533                                  struct dx_frame *frames,
 534                                  __u32 *start_hash)
 535 {
 536         struct dx_frame *p;
 537         struct buffer_head *bh;
 538         int err, num_frames = 0;
 539         __u32 bhash;
 540
 541         p = frame;
 542         /*
 543          * Find the next leaf page by incrementing the frame pointer.
 544          * If we run out of entries in the interior node, loop around and
 545          * increment pointer in the parent node.  When we break out of
 546          * this loop, num_frames indicates the number of interior
 547          * nodes need to be read.
 548          */
 549         while (1) {
 550                 if (++(p->at) < p->entries + dx_get_count(p->entries))
 551                         break;
 552                 if (p == frames)
 553                         return 0;
 554                 num_frames++;
 555                 p--;
 556         }
 557
 558         /*
 559          * If the hash is 1, then continue only if the next page has a
 560          * continuation hash of any value.  This is used for readdir
 561          * handling.  Otherwise, check to see if the hash matches the
 562          * desired contiuation hash.  If it doesn't, return since
 563          * there's no point to read in the successive index pages.
 564          */
 565         bhash = dx_get_hash(p->at);
 566         if (start_hash)
 567                 *start_hash = bhash;
 568         if ((hash & 1) == 0) {
 569                 if ((bhash & ~1) != hash)
 570                         return 0;
 571         }
 572         /*
 573          * If the hash is HASH_NB_ALWAYS, we always go to the next
 574          * block so no check is necessary
 575          */
 576         while (num_frames--) {
 577                 if (!(bh = ext4_bread(NULL, dir, dx_get_block(p->at),
 578                                       0, &err)))
 579                         return err; /* Failure */
 580                 p++;
 581                 brelse(p->bh);
 582                 p->bh = bh;
 583                 p->at = p->entries = ((struct dx_node *) bh->b_data)->entries;
 584         }
 585         return 1;
 586 }
 587
 588
 589 /*
 590  * This function fills a red-black tree with information from a
 591  * directory block.  It returns the number directory entries loaded
 592  * into the tree.  If there is an error it is returned in err.
 593  */
 594 static int htree_dirblock_to_tree(struct file *dir_file,
 595                                   struct inode *dir, ext4_lblk_t block,
 596                                   struct dx_hash_info *hinfo,
 597                                   __u32 start_hash, __u32 start_minor_hash)
 598 {
 599         struct buffer_head *bh;
 600         struct ext4_dir_entry_2 *de, *top;
 601         int err, count = 0;
 602
 603         dxtrace(printk(KERN_INFO "In htree dirblock_to_tree: block %lu\n",
 604                                                         (unsigned long)block));
 605         if (!(bh = ext4_bread (NULL, dir, block, 0, &err)))
 606                 return err;
 607
 608         de = (struct ext4_dir_entry_2 *) bh->b_data;
 609         top = (struct ext4_dir_entry_2 *) ((char *) de +
 610                                            dir->i_sb->s_blocksize -
 611                                            EXT4_DIR_REC_LEN(0));
 612         for (; de < top; de = ext4_next_entry(de, dir->i_sb->s_blocksize)) {
 613                 if (!ext4_check_dir_entry("htree_dirblock_to_tree", dir, de, bh,
 614                                         (block<<EXT4_BLOCK_SIZE_BITS(dir->i_sb))
 615                                                 +((char *)de - bh->b_data))) {
 616                         /* On error, skip the f_pos to the next block. */
 617                         dir_file->f_pos = (dir_file->f_pos |
 618                                         (dir->i_sb->s_blocksize - 1)) + 1;
 619                         brelse(bh);
 620                         return count;
 621                 }
 622                 ext4fs_dirhash(de->name, de->name_len, hinfo);
 623                 if ((hinfo->hash < start_hash) ||
 624                     ((hinfo->hash == start_hash) &&
 625                      (hinfo->minor_hash < start_minor_hash)))
 626                         continue;
 627                 if (de->inode == 0)
 628                         continue;
 629                 if ((err = ext4_htree_store_dirent(dir_file,
 630                                    hinfo->hash, hinfo->minor_hash, de)) != 0) {
 631                         brelse(bh);
 632                         return err;
 633                 }
 634                 count++;
 635         }
 636         brelse(bh);
 637         return count;
 638 }
 639
 640
 641 /*
 642  * This function fills a red-black tree with information from a
 643  * directory.  We start scanning the directory in hash order, starting
 644  * at start_hash and start_minor_hash.
 645  *
 646  * This function returns the number of entries inserted into the tree,
 647  * or a negative error code.
 648  */
 649 int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash,
 650                          __u32 start_minor_hash, __u32 *next_hash)
 651 {
 652         struct dx_hash_info hinfo;
 653         struct ext4_dir_entry_2 *de;
 654         struct dx_frame frames[2], *frame;
 655         struct inode *dir;
 656         ext4_lblk_t block;
 657         int count = 0;
 658         int ret, err;
 659         __u32 hashval;
 660
 661         dxtrace(printk(KERN_DEBUG "In htree_fill_tree, start hash: %x:%x\n",
 662                        start_hash, start_minor_hash));
 663         dir = dir_file->f_path.dentry->d_inode;
 664         if (!(EXT4_I(dir)->i_flags & EXT4_INDEX_FL)) {
 665                 hinfo.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
 666                 if (hinfo.hash_version <= DX_HASH_TEA)
 667                         hinfo.hash_version +=
 668                                 EXT4_SB(dir->i_sb)->s_hash_unsigned;
 669                 hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
 670                 count = htree_dirblock_to_tree(dir_file, dir, 0, &hinfo,
 671                                                start_hash, start_minor_hash);
 672                 *next_hash = ~0;
 673                 return count;
 674         }
 675         hinfo.hash = start_hash;
 676         hinfo.minor_hash = 0;
 677         frame = dx_probe(NULL, dir, &hinfo, frames, &err);
 678         if (!frame)
 679                 return err;
 680
 681         /* Add '.' and '..' from the htree header */
 682         if (!start_hash && !start_minor_hash) {
 683                 de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data;
 684                 if ((err = ext4_htree_store_dirent(dir_file, 0, 0, de)) != 0)
 685                         goto errout;
 686                 count++;
 687         }
 688         if (start_hash < 2 || (start_hash ==2 && start_minor_hash==0)) {
 689                 de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data;
 690                 de = ext4_next_entry(de, dir->i_sb->s_blocksize);
 691                 if ((err = ext4_htree_store_dirent(dir_file, 2, 0, de)) != 0)
 692                         goto errout;
 693                 count++;
 694         }
 695
 696         while (1) {
 697                 block = dx_get_block(frame->at);
 698                 ret = htree_dirblock_to_tree(dir_file, dir, block, &hinfo,
 699                                              start_hash, start_minor_hash);
 700                 if (ret < 0) {
 701                         err = ret;
 702                         goto errout;
 703                 }
 704                 count += ret;
 705                 hashval = ~0;
 706                 ret = ext4_htree_next_block(dir, HASH_NB_ALWAYS,
 707                                             frame, frames, &hashval);
 708                 *next_hash = hashval;
 709                 if (ret < 0) {
 710                         err = ret;
 711                         goto errout;
 712                 }
 713                 /*
 714                  * Stop if:  (a) there are no more entries, or
 715                  * (b) we have inserted at least one entry and the
 716                  * next hash value is not a continuation
 717                  */
 718                 if ((ret == 0) ||
 719                     (count && ((hashval & 1) == 0)))
 720                         break;
 721         }
 722         dx_release(frames);
 723         dxtrace(printk(KERN_DEBUG "Fill tree: returned %d entries, "
 724                        "next hash: %x\n", count, *next_hash));
 725         return count;
 726 errout:
 727         dx_release(frames);
 728         return (err);
 729 }
 730
 731
 732 /*
 733  * Directory block splitting, compacting
 734  */
 735
 736 /*
 737  * Create map of hash values, offsets, and sizes, stored at end of block.
 738  * Returns number of entries mapped.
 739  */
 740 static int dx_make_map(struct ext4_dir_entry_2 *de, unsigned blocksize,
 741                        struct dx_hash_info *hinfo,
 742                        struct dx_map_entry *map_tail)
 743 {
 744         int count = 0;
 745         char *base = (char *) de;
 746         struct dx_hash_info h = *hinfo;
 747
 748         while ((char *) de < base + blocksize) {
 749                 if (de->name_len && de->inode) {
 750                         ext4fs_dirhash(de->name, de->name_len, &h);
 751                         map_tail--;
 752                         map_tail->hash = h.hash;
 753                         map_tail->offs = (u16) ((char *) de - base);
 754                         map_tail->size = le16_to_cpu(de->rec_len);
 755                         count++;
 756                         cond_resched();
 757                 }
 758                 /* XXX: do we need to check rec_len == 0 case? -Chris */
 759                 de = ext4_next_entry(de, blocksize);
 760         }
 761         return count;
 762 }
 763
 764 /* Sort map by hash value */
 765 static void dx_sort_map (struct dx_map_entry *map, unsigned count)
 766 {
 767         struct dx_map_entry *p, *q, *top = map + count - 1;
 768         int more;
 769         /* Combsort until bubble sort doesn't suck */
 770         while (count > 2) {
 771                 count = count*10/13;
 772                 if (count - 9 < 2) /* 9, 10 -> 11 */
 773                         count = 11;
 774                 for (p = top, q = p - count; q >= map; p--, q--)
 775                         if (p->hash < q->hash)
 776                                 swap(*p, *q);
 777         }
 778         /* Garden variety bubble sort */
 779         do {
 780                 more = 0;
 781                 q = top;
 782                 while (q-- > map) {
 783                         if (q[1].hash >= q[0].hash)
 784                                 continue;
 785                         swap(*(q+1), *q);
 786                         more = 1;
 787                 }
 788         } while(more);
 789 }
 790
 791 static void dx_insert_block(struct dx_frame *frame, u32 hash, ext4_lblk_t block)
 792 {
 793         struct dx_entry *entries = frame->entries;
 794         struct dx_entry *old = frame->at, *new = old + 1;
 795         int count = dx_get_count(entries);
 796
 797         assert(count < dx_get_limit(entries));
 798         assert(old < entries + count);
 799         memmove(new + 1, new, (char *)(entries + count) - (char *)(new));
 800         dx_set_hash(new, hash);
 801         dx_set_block(new, block);
 802         dx_set_count(entries, count + 1);
 803 }
 804
 805 static void ext4_update_dx_flag(struct inode *inode)
 806 {
 807         if (!EXT4_HAS_COMPAT_FEATURE(inode->i_sb,
 808                                      EXT4_FEATURE_COMPAT_DIR_INDEX))
 809                 EXT4_I(inode)->i_flags &= ~EXT4_INDEX_FL;
 810 }
 811
 812 /*
 813  * NOTE! unlike strncmp, ext4_match returns 1 for success, 0 for failure.
 814  *
 815  * `len <= EXT4_NAME_LEN' is guaranteed by caller.
 816  * `de != NULL' is guaranteed by caller.
 817  */
 818 static inline int ext4_match (int len, const char * const name,
 819                               struct ext4_dir_entry_2 * de)
 820 {
 821         if (len != de->name_len)
 822                 return 0;
 823         if (!de->inode)
 824                 return 0;
 825         return !memcmp(name, de->name, len);
 826 }
 827
 828 /*
 829  * Returns 0 if not found, -1 on failure, and 1 on success
 830  */
 831 static inline int search_dirblock(struct buffer_head *bh,
 832                                   struct inode *dir,
 833                                   const struct qstr *d_name,
 834                                   unsigned int offset,
 835                                   struct ext4_dir_entry_2 ** res_dir)
 836 {
 837         struct ext4_dir_entry_2 * de;
 838         char * dlimit;
 839         int de_len;
 840         const char *name = d_name->name;
 841         int namelen = d_name->len;
 842
 843         de = (struct ext4_dir_entry_2 *) bh->b_data;
 844         dlimit = bh->b_data + dir->i_sb->s_blocksize;
 845         while ((char *) de < dlimit) {
 846                 /* this code is executed quadratically often */
 847                 /* do minimal checking `by hand' */
 848
 849                 if ((char *) de + namelen <= dlimit &&
 850                     ext4_match (namelen, name, de)) {
 851                         /* found a match - just to be sure, do a full check */
 852                         if (!ext4_check_dir_entry("ext4_find_entry",
 853                                                   dir, de, bh, offset))
 854                                 return -1;
 855                         *res_dir = de;
 856                         return 1;
 857                 }
 858                 /* prevent looping on a bad block */
 859                 de_len = ext4_rec_len_from_disk(de->rec_len,
 860                                                 dir->i_sb->s_blocksize);
 861                 if (de_len <= 0)
 862                         return -1;
 863                 offset += de_len;
 864                 de = (struct ext4_dir_entry_2 *) ((char *) de + de_len);
 865         }
 866         return 0;
 867 }
 868
 869
 870 /*
 871  *      ext4_find_entry()
 872  *
 873  * finds an entry in the specified directory with the wanted name. It
 874  * returns the cache buffer in which the entry was found, and the entry
 875  * itself (as a parameter - res_dir). It does NOT read the inode of the
 876  * entry - you'll have to do that yourself if you want to.
 877  *
 878  * The returned buffer_head has ->b_count elevated.  The caller is expected
 879  * to brelse() it when appropriate.
 880  */
 881 static struct buffer_head * ext4_find_entry (struct inode *dir,
 882                                         const struct qstr *d_name,
 883                                         struct ext4_dir_entry_2 ** res_dir)
 884 {
 885         struct super_block *sb;
 886         struct buffer_head *bh_use[NAMEI_RA_SIZE];
 887         struct buffer_head *bh, *ret = NULL;
 888         ext4_lblk_t start, block, b;
 889         int ra_max = 0;         /* Number of bh's in the readahead
 890                                    buffer, bh_use[] */
 891         int ra_ptr = 0;         /* Current index into readahead
 892                                    buffer */
 893         int num = 0;
 894         ext4_lblk_t  nblocks;
 895         int i, err;
 896         int namelen;
 897
 898         *res_dir = NULL;
 899         sb = dir->i_sb;
 900         namelen = d_name->len;
 901         if (namelen > EXT4_NAME_LEN)
 902                 return NULL;
 903         if (is_dx(dir)) {
 904                 bh = ext4_dx_find_entry(dir, d_name, res_dir, &err);
 905                 /*
 906                  * On success, or if the error was file not found,
 907                  * return.  Otherwise, fall back to doing a search the
 908                  * old fashioned way.
 909                  */
 910                 if (bh || (err != ERR_BAD_DX_DIR))
 911                         return bh;
 912                 dxtrace(printk(KERN_DEBUG "ext4_find_entry: dx failed, "
 913                                "falling back\n"));
 914         }
 915         nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb);
 916         start = EXT4_I(dir)->i_dir_start_lookup;
 917         if (start >= nblocks)
 918                 start = 0;
 919         block = start;
 920 restart:
 921         do {
 922                 /*
 923                  * We deal with the read-ahead logic here.
 924                  */
 925                 if (ra_ptr >= ra_max) {
 926                         /* Refill the readahead buffer */
 927                         ra_ptr = 0;
 928                         b = block;
 929                         for (ra_max = 0; ra_max < NAMEI_RA_SIZE; ra_max++) {
 930                                 /*
 931                                  * Terminate if we reach the end of the
 932                                  * directory and must wrap, or if our
 933                                  * search has finished at this block.
 934                                  */
 935                                 if (b >= nblocks || (num && block == start)) {
 936                                         bh_use[ra_max] = NULL;
 937                                         break;
 938                                 }
 939                                 num++;
 940                                 bh = ext4_getblk(NULL, dir, b++, 0, &err);
 941                                 bh_use[ra_max] = bh;
 942                                 if (bh)
 943                                         ll_rw_block(READ_META, 1, &bh);
 944                         }
 945                 }
 946                 if ((bh = bh_use[ra_ptr++]) == NULL)
 947                         goto next;
 948                 wait_on_buffer(bh);
 949                 if (!buffer_uptodate(bh)) {
 950                         /* read error, skip block & hope for the best */
 951                         ext4_error(sb, __func__, "reading directory #%lu "
 952                                    "offset %lu", dir->i_ino,
 953                                    (unsigned long)block);
 954                         brelse(bh);
 955                         goto next;
 956                 }
 957                 i = search_dirblock(bh, dir, d_name,
 958                             block << EXT4_BLOCK_SIZE_BITS(sb), res_dir);
 959                 if (i == 1) {
 960                         EXT4_I(dir)->i_dir_start_lookup = block;
 961                         ret = bh;
 962                         goto cleanup_and_exit;
 963                 } else {
 964                         brelse(bh);
 965                         if (i < 0)
 966                                 goto cleanup_and_exit;
 967                 }
 968         next:
 969                 if (++block >= nblocks)
 970                         block = 0;
 971         } while (block != start);
 972
 973         /*
 974          * If the directory has grown while we were searching, then
 975          * search the last part of the directory before giving up.
 976          */
 977         block = nblocks;
 978         nblocks = dir->i_size >> EXT4_BLOCK_SIZE_BITS(sb);
 979         if (block < nblocks) {
 980                 start = 0;
 981                 goto restart;
 982         }
 983
 984 cleanup_and_exit:
 985         /* Clean up the read-ahead blocks */
 986         for (; ra_ptr < ra_max; ra_ptr++)
 987                 brelse(bh_use[ra_ptr]);
 988         return ret;
 989 }
 990
 991 static struct buffer_head * ext4_dx_find_entry(struct inode *dir, const struct qstr *d_name,
 992                        struct ext4_dir_entry_2 **res_dir, int *err)
 993 {
 994         struct super_block * sb;
 995         struct dx_hash_info     hinfo;
 996         u32 hash;
 997         struct dx_frame frames[2], *frame;
 998         struct ext4_dir_entry_2 *de, *top;
 999         struct buffer_head *bh;
1000         ext4_lblk_t block;
1001         int retval;
1002         int namelen = d_name->len;
1003         const u8 *name = d_name->name;
1004
1005         sb = dir->i_sb;
1006         /* NFS may look up ".." - look at dx_root directory block */
1007         if (namelen > 2 || name[0] != '.'||(name[1] != '.' && name[1] != '\0')){
1008                 if (!(frame = dx_probe(d_name, dir, &hinfo, frames, err)))
1009                         return NULL;
1010         } else {
1011                 frame = frames;
1012                 frame->bh = NULL;                       /* for dx_release() */
1013                 frame->at = (struct dx_entry *)frames;  /* hack for zero entry*/
1014                 dx_set_block(frame->at, 0);             /* dx_root block is 0 */
1015         }
1016         hash = hinfo.hash;
1017         do {
1018                 block = dx_get_block(frame->at);
1019                 if (!(bh = ext4_bread (NULL,dir, block, 0, err)))
1020                         goto errout;
1021                 de = (struct ext4_dir_entry_2 *) bh->b_data;
1022                 top = (struct ext4_dir_entry_2 *) ((char *) de + sb->s_blocksize -
1023                                        EXT4_DIR_REC_LEN(0));
1024                 for (; de < top; de = ext4_next_entry(de, sb->s_blocksize)) {
1025                         int off = (block << EXT4_BLOCK_SIZE_BITS(sb))
1026                                   + ((char *) de - bh->b_data);
1027
1028                         if (!ext4_check_dir_entry(__func__, dir, de, bh, off)) {
1029                                 brelse(bh);
1030                                 *err = ERR_BAD_DX_DIR;
1031                                 goto errout;
1032                         }
1033
1034                         if (ext4_match(namelen, name, de)) {
1035                                 *res_dir = de;
1036                                 dx_release(frames);
1037                                 return bh;
1038                         }
1039                 }
1040                 brelse(bh);
1041                 /* Check to see if we should continue to search */
1042                 retval = ext4_htree_next_block(dir, hash, frame,
1043                                                frames, NULL);
1044                 if (retval < 0) {
1045                         ext4_warning(sb, __func__,
1046                              "error reading index page in directory #%lu",
1047                              dir->i_ino);
1048                         *err = retval;
1049                         goto errout;
1050                 }
1051         } while (retval == 1);
1052
1053         *err = -ENOENT;
1054 errout:
1055         dxtrace(printk(KERN_DEBUG "%s not found\n", name));
1056         dx_release (frames);
1057         return NULL;
1058 }
1059
1060 static struct dentry *ext4_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd)
1061 {
1062         struct inode *inode;
1063         struct ext4_dir_entry_2 *de;
1064         struct buffer_head *bh;
1065
1066         if (dentry->d_name.len > EXT4_NAME_LEN)
1067                 return ERR_PTR(-ENAMETOOLONG);
1068
1069         bh = ext4_find_entry(dir, &dentry->d_name, &de);
1070         inode = NULL;
1071         if (bh) {
1072                 __u32 ino = le32_to_cpu(de->inode);
1073                 brelse(bh);
1074                 if (!ext4_valid_inum(dir->i_sb, ino)) {
1075                         ext4_error(dir->i_sb, "ext4_lookup",
1076                                    "bad inode number: %u", ino);
1077                         return ERR_PTR(-EIO);
1078                 }
1079                 inode = ext4_iget(dir->i_sb, ino);
1080                 if (unlikely(IS_ERR(inode))) {
1081                         if (PTR_ERR(inode) == -ESTALE) {
1082                                 ext4_error(dir->i_sb, __func__,
1083                                                 "deleted inode referenced: %u",
1084                                                 ino);
1085                                 return ERR_PTR(-EIO);
1086                         } else {
1087                                 return ERR_CAST(inode);
1088                         }
1089                 }
1090         }
1091         return d_splice_alias(inode, dentry);
1092 }
1093
1094
1095 struct dentry *ext4_get_parent(struct dentry *child)
1096 {
1097         __u32 ino;
1098         struct inode *inode;
1099         static const struct qstr dotdot = {
1100                 .name = "..",
1101                 .len = 2,
1102         };
1103         struct ext4_dir_entry_2 * de;
1104         struct buffer_head *bh;
1105
1106         bh = ext4_find_entry(child->d_inode, &dotdot, &de);
1107         inode = NULL;
1108         if (!bh)
1109                 return ERR_PTR(-ENOENT);
1110         ino = le32_to_cpu(de->inode);
1111         brelse(bh);
1112
1113         if (!ext4_valid_inum(child->d_inode->i_sb, ino)) {
1114                 ext4_error(child->d_inode->i_sb, "ext4_get_parent",
1115                            "bad inode number: %u", ino);
1116                 return ERR_PTR(-EIO);
1117         }
1118
1119         return d_obtain_alias(ext4_iget(child->d_inode->i_sb, ino));
1120 }
1121
1122 #define S_SHIFT 12
1123 static unsigned char ext4_type_by_mode[S_IFMT >> S_SHIFT] = {
1124         [S_IFREG >> S_SHIFT]    = EXT4_FT_REG_FILE,
1125         [S_IFDIR >> S_SHIFT]    = EXT4_FT_DIR,
1126         [S_IFCHR >> S_SHIFT]    = EXT4_FT_CHRDEV,
1127         [S_IFBLK >> S_SHIFT]    = EXT4_FT_BLKDEV,
1128         [S_IFIFO >> S_SHIFT]    = EXT4_FT_FIFO,
1129         [S_IFSOCK >> S_SHIFT]   = EXT4_FT_SOCK,
1130         [S_IFLNK >> S_SHIFT]    = EXT4_FT_SYMLINK,
1131 };
1132
1133 static inline void ext4_set_de_type(struct super_block *sb,
1134                                 struct ext4_dir_entry_2 *de,
1135                                 umode_t mode) {
1136         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FILETYPE))
1137                 de->file_type = ext4_type_by_mode[(mode & S_IFMT)>>S_SHIFT];
1138 }
1139
1140 /*
1141  * Move count entries from end of map between two memory locations.
1142  * Returns pointer to last entry moved.
1143  */
1144 static struct ext4_dir_entry_2 *
1145 dx_move_dirents(char *from, char *to, struct dx_map_entry *map, int count,
1146                 unsigned blocksize)
1147 {
1148         unsigned rec_len = 0;
1149
1150         while (count--) {
1151                 struct ext4_dir_entry_2 *de = (struct ext4_dir_entry_2 *) (from + map->offs);
1152                 rec_len = EXT4_DIR_REC_LEN(de->name_len);
1153                 memcpy (to, de, rec_len);
1154                 ((struct ext4_dir_entry_2 *) to)->rec_len =
1155                                 ext4_rec_len_to_disk(rec_len, blocksize);
1156                 de->inode = 0;
1157                 map++;
1158                 to += rec_len;
1159         }
1160         return (struct ext4_dir_entry_2 *) (to - rec_len);
1161 }
1162
1163 /*
1164  * Compact each dir entry in the range to the minimal rec_len.
1165  * Returns pointer to last entry in range.
1166  */
1167 static struct ext4_dir_entry_2* dx_pack_dirents(char *base, unsigned blocksize)
1168 {
1169         struct ext4_dir_entry_2 *next, *to, *prev, *de = (struct ext4_dir_entry_2 *) base;
1170         unsigned rec_len = 0;
1171
1172         prev = to = de;
1173         while ((char*)de < base + blocksize) {
1174                 next = ext4_next_entry(de, blocksize);
1175                 if (de->inode && de->name_len) {
1176                         rec_len = EXT4_DIR_REC_LEN(de->name_len);
1177                         if (de > to)
1178                                 memmove(to, de, rec_len);
1179                         to->rec_len = ext4_rec_len_to_disk(rec_len, blocksize);
1180                         prev = to;
1181                         to = (struct ext4_dir_entry_2 *) (((char *) to) + rec_len);
1182                 }
1183                 de = next;
1184         }
1185         return prev;
1186 }
1187
1188 /*
1189  * Split a full leaf block to make room for a new dir entry.
1190  * Allocate a new block, and move entries so that they are approx. equally full.
1191  * Returns pointer to de in block into which the new entry will be inserted.
1192  */
1193 static struct ext4_dir_entry_2 *do_split(handle_t *handle, struct inode *dir,
1194                         struct buffer_head **bh,struct dx_frame *frame,
1195                         struct dx_hash_info *hinfo, int *error)
1196 {
1197         unsigned blocksize = dir->i_sb->s_blocksize;
1198         unsigned count, continued;
1199         struct buffer_head *bh2;
1200         ext4_lblk_t newblock;
1201         u32 hash2;
1202         struct dx_map_entry *map;
1203         char *data1 = (*bh)->b_data, *data2;
1204         unsigned split, move, size;
1205         struct ext4_dir_entry_2 *de = NULL, *de2;
1206         int     err = 0, i;
1207
1208         bh2 = ext4_append (handle, dir, &newblock, &err);
1209         if (!(bh2)) {
1210                 brelse(*bh);
1211                 *bh = NULL;
1212                 goto errout;
1213         }
1214
1215         BUFFER_TRACE(*bh, "get_write_access");
1216         err = ext4_journal_get_write_access(handle, *bh);
1217         if (err)
1218                 goto journal_error;
1219
1220         BUFFER_TRACE(frame->bh, "get_write_access");
1221         err = ext4_journal_get_write_access(handle, frame->bh);
1222         if (err)
1223                 goto journal_error;
1224
1225         data2 = bh2->b_data;
1226
1227         /* create map in the end of data2 block */
1228         map = (struct dx_map_entry *) (data2 + blocksize);
1229         count = dx_make_map((struct ext4_dir_entry_2 *) data1,
1230                              blocksize, hinfo, map);
1231         map -= count;
1232         dx_sort_map(map, count);
1233         /* Split the existing block in the middle, size-wise */
1234         size = 0;
1235         move = 0;
1236         for (i = count-1; i >= 0; i--) {
1237                 /* is more than half of this entry in 2nd half of the block? */
1238                 if (size + map[i].size/2 > blocksize/2)
1239                         break;
1240                 size += map[i].size;
1241                 move++;
1242         }
1243         /* map index at which we will split */
1244         split = count - move;
1245         hash2 = map[split].hash;
1246         continued = hash2 == map[split - 1].hash;
1247         dxtrace(printk(KERN_INFO "Split block %lu at %x, %i/%i\n",
1248                         (unsigned long)dx_get_block(frame->at),
1249                                         hash2, split, count-split));
1250
1251         /* Fancy dance to stay within two buffers */
1252         de2 = dx_move_dirents(data1, data2, map + split, count - split, blocksize);
1253         de = dx_pack_dirents(data1, blocksize);
1254         de->rec_len = ext4_rec_len_to_disk(data1 + blocksize - (char *) de,
1255                                            blocksize);
1256         de2->rec_len = ext4_rec_len_to_disk(data2 + blocksize - (char *) de2,
1257                                             blocksize);
1258         dxtrace(dx_show_leaf (hinfo, (struct ext4_dir_entry_2 *) data1, blocksize, 1));
1259         dxtrace(dx_show_leaf (hinfo, (struct ext4_dir_entry_2 *) data2, blocksize, 1));
1260
1261         /* Which block gets the new entry? */
1262         if (hinfo->hash >= hash2)
1263         {
1264                 swap(*bh, bh2);
1265                 de = de2;
1266         }
1267         dx_insert_block(frame, hash2 + continued, newblock);
1268         err = ext4_handle_dirty_metadata(handle, dir, bh2);
1269         if (err)
1270                 goto journal_error;
1271         err = ext4_handle_dirty_metadata(handle, dir, frame->bh);
1272         if (err)
1273                 goto journal_error;
1274         brelse(bh2);
1275         dxtrace(dx_show_index("frame", frame->entries));
1276         return de;
1277
1278 journal_error:
1279         brelse(*bh);
1280         brelse(bh2);
1281         *bh = NULL;
1282         ext4_std_error(dir->i_sb, err);
1283 errout:
1284         *error = err;
1285         return NULL;
1286 }
1287
1288 /*
1289  * Add a new entry into a directory (leaf) block.  If de is non-NULL,
1290  * it points to a directory entry which is guaranteed to be large
1291  * enough for new directory entry.  If de is NULL, then
1292  * add_dirent_to_buf will attempt search the directory block for
1293  * space.  It will return -ENOSPC if no space is available, and -EIO
1294  * and -EEXIST if directory entry already exists.
1295  *
1296  * NOTE!  bh is NOT released in the case where ENOSPC is returned.  In
1297  * all other cases bh is released.
1298  */
1299 static int add_dirent_to_buf(handle_t *handle, struct dentry *dentry,
1300                              struct inode *inode, struct ext4_dir_entry_2 *de,
1301                              struct buffer_head *bh)
1302 {
1303         struct inode    *dir = dentry->d_parent->d_inode;
1304         const char      *name = dentry->d_name.name;
1305         int             namelen = dentry->d_name.len;
1306         unsigned int    offset = 0;
1307         unsigned int    blocksize = dir->i_sb->s_blocksize;
1308         unsigned short  reclen;
1309         int             nlen, rlen, err;
1310         char            *top;
1311
1312         reclen = EXT4_DIR_REC_LEN(namelen);
1313         if (!de) {
1314                 de = (struct ext4_dir_entry_2 *)bh->b_data;
1315                 top = bh->b_data + blocksize - reclen;
1316                 while ((char *) de <= top) {
1317                         if (!ext4_check_dir_entry("ext4_add_entry", dir, de,
1318                                                   bh, offset)) {
1319                                 brelse(bh);
1320                                 return -EIO;
1321                         }
1322                         if (ext4_match(namelen, name, de)) {
1323                                 brelse(bh);
1324                                 return -EEXIST;
1325                         }
1326                         nlen = EXT4_DIR_REC_LEN(de->name_len);
1327                         rlen = ext4_rec_len_from_disk(de->rec_len, blocksize);
1328                         if ((de->inode? rlen - nlen: rlen) >= reclen)
1329                                 break;
1330                         de = (struct ext4_dir_entry_2 *)((char *)de + rlen);
1331                         offset += rlen;
1332                 }
1333                 if ((char *) de > top)
1334                         return -ENOSPC;
1335         }
1336         BUFFER_TRACE(bh, "get_write_access");
1337         err = ext4_journal_get_write_access(handle, bh);
1338         if (err) {
1339                 ext4_std_error(dir->i_sb, err);
1340                 brelse(bh);
1341                 return err;
1342         }
1343
1344         /* By now the buffer is marked for journaling */
1345         nlen = EXT4_DIR_REC_LEN(de->name_len);
1346         rlen = ext4_rec_len_from_disk(de->rec_len, blocksize);
1347         if (de->inode) {
1348                 struct ext4_dir_entry_2 *de1 = (struct ext4_dir_entry_2 *)((char *)de + nlen);
1349                 de1->rec_len = ext4_rec_len_to_disk(rlen - nlen, blocksize);
1350                 de->rec_len = ext4_rec_len_to_disk(nlen, blocksize);
1351                 de = de1;
1352         }
1353         de->file_type = EXT4_FT_UNKNOWN;
1354         if (inode) {
1355                 de->inode = cpu_to_le32(inode->i_ino);
1356                 ext4_set_de_type(dir->i_sb, de, inode->i_mode);
1357         } else
1358                 de->inode = 0;
1359         de->name_len = namelen;
1360         memcpy(de->name, name, namelen);
1361         /*
1362          * XXX shouldn't update any times until successful
1363          * completion of syscall, but too many callers depend
1364          * on this.
1365          *
1366          * XXX similarly, too many callers depend on
1367          * ext4_new_inode() setting the times, but error
1368          * recovery deletes the inode, so the worst that can
1369          * happen is that the times are slightly out of date
1370          * and/or different from the directory change time.
1371          */
1372         dir->i_mtime = dir->i_ctime = ext4_current_time(dir);
1373         ext4_update_dx_flag(dir);
1374         dir->i_version++;
1375         ext4_mark_inode_dirty(handle, dir);
1376         BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
1377         err = ext4_handle_dirty_metadata(handle, dir, bh);
1378         if (err)
1379                 ext4_std_error(dir->i_sb, err);
1380         brelse(bh);
1381         return 0;
1382 }
1383
1384 /*
1385  * This converts a one block unindexed directory to a 3 block indexed
1386  * directory, and adds the dentry to the indexed directory.
1387  */
1388 static int make_indexed_dir(handle_t *handle, struct dentry *dentry,
1389                             struct inode *inode, struct buffer_head *bh)
1390 {
1391         struct inode    *dir = dentry->d_parent->d_inode;
1392         const char      *name = dentry->d_name.name;
1393         int             namelen = dentry->d_name.len;
1394         struct buffer_head *bh2;
1395         struct dx_root  *root;
1396         struct dx_frame frames[2], *frame;
1397         struct dx_entry *entries;
1398         struct ext4_dir_entry_2 *de, *de2;
1399         char            *data1, *top;
1400         unsigned        len;
1401         int             retval;
1402         unsigned        blocksize;
1403         struct dx_hash_info hinfo;
1404         ext4_lblk_t  block;
1405         struct fake_dirent *fde;
1406
1407         blocksize =  dir->i_sb->s_blocksize;
1408         dxtrace(printk(KERN_DEBUG "Creating index: inode %lu\n", dir->i_ino));
1409         retval = ext4_journal_get_write_access(handle, bh);
1410         if (retval) {
1411                 ext4_std_error(dir->i_sb, retval);
1412                 brelse(bh);
1413                 return retval;
1414         }
1415         root = (struct dx_root *) bh->b_data;
1416
1417         /* The 0th block becomes the root, move the dirents out */
1418         fde = &root->dotdot;
1419         de = (struct ext4_dir_entry_2 *)((char *)fde +
1420                 ext4_rec_len_from_disk(fde->rec_len, blocksize));
1421         if ((char *) de >= (((char *) root) + blocksize)) {
1422                 ext4_error(dir->i_sb, __func__,
1423                            "invalid rec_len for '..' in inode %lu",
1424                            dir->i_ino);
1425                 brelse(bh);
1426                 return -EIO;
1427         }
1428         len = ((char *) root) + blocksize - (char *) de;
1429
1430         /* Allocate new block for the 0th block's dirents */
1431         bh2 = ext4_append(handle, dir, &block, &retval);
1432         if (!(bh2)) {
1433                 brelse(bh);
1434                 return retval;
1435         }
1436         EXT4_I(dir)->i_flags |= EXT4_INDEX_FL;
1437         data1 = bh2->b_data;
1438
1439         memcpy (data1, de, len);
1440         de = (struct ext4_dir_entry_2 *) data1;
1441         top = data1 + len;
1442         while ((char *)(de2 = ext4_next_entry(de, blocksize)) < top)
1443                 de = de2;
1444         de->rec_len = ext4_rec_len_to_disk(data1 + blocksize - (char *) de,
1445                                            blocksize);
1446         /* Initialize the root; the dot dirents already exist */
1447         de = (struct ext4_dir_entry_2 *) (&root->dotdot);
1448         de->rec_len = ext4_rec_len_to_disk(blocksize - EXT4_DIR_REC_LEN(2),
1449                                            blocksize);
1450         memset (&root->info, 0, sizeof(root->info));
1451         root->info.info_length = sizeof(root->info);
1452         root->info.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
1453         entries = root->entries;
1454         dx_set_block(entries, 1);
1455         dx_set_count(entries, 1);
1456         dx_set_limit(entries, dx_root_limit(dir, sizeof(root->info)));
1457
1458         /* Initialize as for dx_probe */
1459         hinfo.hash_version = root->info.hash_version;
1460         if (hinfo.hash_version <= DX_HASH_TEA)
1461                 hinfo.hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
1462         hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
1463         ext4fs_dirhash(name, namelen, &hinfo);
1464         frame = frames;
1465         frame->entries = entries;
1466         frame->at = entries;
1467         frame->bh = bh;
1468         bh = bh2;
1469         de = do_split(handle,dir, &bh, frame, &hinfo, &retval);
1470         dx_release (frames);
1471         if (!(de))
1472                 return retval;
1473
1474         return add_dirent_to_buf(handle, dentry, inode, de, bh);
1475 }
1476
1477 /*
1478  *      ext4_add_entry()
1479  *
1480  * adds a file entry to the specified directory, using the same
1481  * semantics as ext4_find_entry(). It returns NULL if it failed.
1482  *
1483  * NOTE!! The inode part of 'de' is left at 0 - which means you
1484  * may not sleep between calling this and putting something into
1485  * the entry, as someone else might have used it while you slept.
1486  */
1487 static int ext4_add_entry(handle_t *handle, struct dentry *dentry,
1488                           struct inode *inode)
1489 {
1490         struct inode *dir = dentry->d_parent->d_inode;
1491         struct buffer_head *bh;
1492         struct ext4_dir_entry_2 *de;
1493         struct super_block *sb;
1494         int     retval;
1495         int     dx_fallback=0;
1496         unsigned blocksize;
1497         ext4_lblk_t block, blocks;
1498
1499         sb = dir->i_sb;
1500         blocksize = sb->s_blocksize;
1501         if (!dentry->d_name.len)
1502                 return -EINVAL;
1503         if (is_dx(dir)) {
1504                 retval = ext4_dx_add_entry(handle, dentry, inode);
1505                 if (!retval || (retval != ERR_BAD_DX_DIR))
1506                         return retval;
1507                 EXT4_I(dir)->i_flags &= ~EXT4_INDEX_FL;
1508                 dx_fallback++;
1509                 ext4_mark_inode_dirty(handle, dir);
1510         }
1511         blocks = dir->i_size >> sb->s_blocksize_bits;
1512         for (block = 0; block < blocks; block++) {
1513                 bh = ext4_bread(handle, dir, block, 0, &retval);
1514                 if(!bh)
1515                         return retval;
1516                 retval = add_dirent_to_buf(handle, dentry, inode, NULL, bh);
1517                 if (retval != -ENOSPC)
1518                         return retval;
1519
1520                 if (blocks == 1 && !dx_fallback &&
1521                     EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_DIR_INDEX))
1522                         return make_indexed_dir(handle, dentry, inode, bh);
1523                 brelse(bh);
1524         }
1525         bh = ext4_append(handle, dir, &block, &retval);
1526         if (!bh)
1527                 return retval;
1528         de = (struct ext4_dir_entry_2 *) bh->b_data;
1529         de->inode = 0;
1530         de->rec_len = ext4_rec_len_to_disk(blocksize, blocksize);
1531         return add_dirent_to_buf(handle, dentry, inode, de, bh);
1532 }
1533
1534 /*
1535  * Returns 0 for success, or a negative error value
1536  */
1537 static int ext4_dx_add_entry(handle_t *handle, struct dentry *dentry,
1538                              struct inode *inode)
1539 {
1540         struct dx_frame frames[2], *frame;
1541         struct dx_entry *entries, *at;
1542         struct dx_hash_info hinfo;
1543         struct buffer_head *bh;
1544         struct inode *dir = dentry->d_parent->d_inode;
1545         struct super_block *sb = dir->i_sb;
1546         struct ext4_dir_entry_2 *de;
1547         int err;
1548
1549         frame = dx_probe(&dentry->d_name, dir, &hinfo, frames, &err);
1550         if (!frame)
1551                 return err;
1552         entries = frame->entries;
1553         at = frame->at;
1554
1555         if (!(bh = ext4_bread(handle,dir, dx_get_block(frame->at), 0, &err)))
1556                 goto cleanup;
1557
1558         BUFFER_TRACE(bh, "get_write_access");
1559         err = ext4_journal_get_write_access(handle, bh);
1560         if (err)
1561                 goto journal_error;
1562
1563         err = add_dirent_to_buf(handle, dentry, inode, NULL, bh);
1564         if (err != -ENOSPC) {
1565                 bh = NULL;
1566                 goto cleanup;
1567         }
1568
1569         /* Block full, should compress but for now just split */
1570         dxtrace(printk(KERN_DEBUG "using %u of %u node entries\n",
1571                        dx_get_count(entries), dx_get_limit(entries)));
1572         /* Need to split index? */
1573         if (dx_get_count(entries) == dx_get_limit(entries)) {
1574                 ext4_lblk_t newblock;
1575                 unsigned icount = dx_get_count(entries);
1576                 int levels = frame - frames;
1577                 struct dx_entry *entries2;
1578                 struct dx_node *node2;
1579                 struct buffer_head *bh2;
1580
1581                 if (levels && (dx_get_count(frames->entries) ==
1582                                dx_get_limit(frames->entries))) {
1583                         ext4_warning(sb, __func__,
1584                                      "Directory index full!");
1585                         err = -ENOSPC;
1586                         goto cleanup;
1587                 }
1588                 bh2 = ext4_append (handle, dir, &newblock, &err);
1589                 if (!(bh2))
1590                         goto cleanup;
1591                 node2 = (struct dx_node *)(bh2->b_data);
1592                 entries2 = node2->entries;
1593                 node2->fake.rec_len = ext4_rec_len_to_disk(sb->s_blocksize,
1594                                                            sb->s_blocksize);
1595                 node2->fake.inode = 0;
1596                 BUFFER_TRACE(frame->bh, "get_write_access");
1597                 err = ext4_journal_get_write_access(handle, frame->bh);
1598                 if (err)
1599                         goto journal_error;
1600                 if (levels) {
1601                         unsigned icount1 = icount/2, icount2 = icount - icount1;
1602                         unsigned hash2 = dx_get_hash(entries + icount1);
1603                         dxtrace(printk(KERN_DEBUG "Split index %i/%i\n",
1604                                        icount1, icount2));
1605
1606                         BUFFER_TRACE(frame->bh, "get_write_access"); /* index root */
1607                         err = ext4_journal_get_write_access(handle,
1608                                                              frames[0].bh);
1609                         if (err)
1610                                 goto journal_error;
1611
1612                         memcpy((char *) entries2, (char *) (entries + icount1),
1613                                icount2 * sizeof(struct dx_entry));
1614                         dx_set_count(entries, icount1);
1615                         dx_set_count(entries2, icount2);
1616                         dx_set_limit(entries2, dx_node_limit(dir));
1617
1618                         /* Which index block gets the new entry? */
1619                         if (at - entries >= icount1) {
1620                                 frame->at = at = at - entries - icount1 + entries2;
1621                                 frame->entries = entries = entries2;
1622                                 swap(frame->bh, bh2);
1623                         }
1624                         dx_insert_block(frames + 0, hash2, newblock);
1625                         dxtrace(dx_show_index("node", frames[1].entries));
1626                         dxtrace(dx_show_index("node",
1627                                ((struct dx_node *) bh2->b_data)->entries));
1628                         err = ext4_handle_dirty_metadata(handle, inode, bh2);
1629                         if (err)
1630                                 goto journal_error;
1631                         brelse (bh2);
1632                 } else {
1633                         dxtrace(printk(KERN_DEBUG
1634                                        "Creating second level index...\n"));
1635                         memcpy((char *) entries2, (char *) entries,
1636                                icount * sizeof(struct dx_entry));
1637                         dx_set_limit(entries2, dx_node_limit(dir));
1638
1639                         /* Set up root */
1640                         dx_set_count(entries, 1);
1641                         dx_set_block(entries + 0, newblock);
1642                         ((struct dx_root *) frames[0].bh->b_data)->info.indirect_levels = 1;
1643
1644                         /* Add new access path frame */
1645                         frame = frames + 1;
1646                         frame->at = at = at - entries + entries2;
1647                         frame->entries = entries = entries2;
1648                         frame->bh = bh2;
1649                         err = ext4_journal_get_write_access(handle,
1650                                                              frame->bh);
1651                         if (err)
1652                                 goto journal_error;
1653                 }
1654                 ext4_handle_dirty_metadata(handle, inode, frames[0].bh);
1655         }
1656         de = do_split(handle, dir, &bh, frame, &hinfo, &err);
1657         if (!de)
1658                 goto cleanup;
1659         err = add_dirent_to_buf(handle, dentry, inode, de, bh);
1660         bh = NULL;
1661         goto cleanup;
1662
1663 journal_error:
1664         ext4_std_error(dir->i_sb, err);
1665 cleanup:
1666         if (bh)
1667                 brelse(bh);
1668         dx_release(frames);
1669         return err;
1670 }
1671
1672 /*
1673  * ext4_delete_entry deletes a directory entry by merging it with the
1674  * previous entry
1675  */
1676 static int ext4_delete_entry(handle_t *handle,
1677                              struct inode *dir,
1678                              struct ext4_dir_entry_2 *de_del,
1679                              struct buffer_head *bh)
1680 {
1681         struct ext4_dir_entry_2 *de, *pde;
1682         unsigned int blocksize = dir->i_sb->s_blocksize;
1683         int i;
1684
1685         i = 0;
1686         pde = NULL;
1687         de = (struct ext4_dir_entry_2 *) bh->b_data;
1688         while (i < bh->b_size) {
1689                 if (!ext4_check_dir_entry("ext4_delete_entry", dir, de, bh, i))
1690                         return -EIO;
1691                 if (de == de_del)  {
1692                         BUFFER_TRACE(bh, "get_write_access");
1693                         ext4_journal_get_write_access(handle, bh);
1694                         if (pde)
1695                                 pde->rec_len = ext4_rec_len_to_disk(
1696                                         ext4_rec_len_from_disk(pde->rec_len,
1697                                                                blocksize) +
1698                                         ext4_rec_len_from_disk(de->rec_len,
1699                                                                blocksize),
1700                                         blocksize);
1701                         else
1702                                 de->inode = 0;
1703                         dir->i_version++;
1704                         BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
1705                         ext4_handle_dirty_metadata(handle, dir, bh);
1706                         return 0;
1707                 }
1708                 i += ext4_rec_len_from_disk(de->rec_len, blocksize);
1709                 pde = de;
1710                 de = ext4_next_entry(de, blocksize);
1711         }
1712         return -ENOENT;
1713 }
1714
1715 /*
1716  * DIR_NLINK feature is set if 1) nlinks > EXT4_LINK_MAX or 2) nlinks == 2,
1717  * since this indicates that nlinks count was previously 1.
1718  */
1719 static void ext4_inc_count(handle_t *handle, struct inode *inode)
1720 {
1721         inc_nlink(inode);
1722         if (is_dx(inode) && inode->i_nlink > 1) {
1723                 /* limit is 16-bit i_links_count */
1724                 if (inode->i_nlink >= EXT4_LINK_MAX || inode->i_nlink == 2) {
1725                         inode->i_nlink = 1;
1726                         EXT4_SET_RO_COMPAT_FEATURE(inode->i_sb,
1727                                               EXT4_FEATURE_RO_COMPAT_DIR_NLINK);
1728                 }
1729         }
1730 }
1731
1732 /*
1733  * If a directory had nlink == 1, then we should let it be 1. This indicates
1734  * directory has >EXT4_LINK_MAX subdirs.
1735  */
1736 static void ext4_dec_count(handle_t *handle, struct inode *inode)
1737 {
1738         drop_nlink(inode);
1739         if (S_ISDIR(inode->i_mode) && inode->i_nlink == 0)
1740                 inc_nlink(inode);
1741 }
1742
1743
1744 static int ext4_add_nondir(handle_t *handle,
1745                 struct dentry *dentry, struct inode *inode)
1746 {
1747         int err = ext4_add_entry(handle, dentry, inode);
1748         if (!err) {
1749                 ext4_mark_inode_dirty(handle, inode);
1750                 d_instantiate(dentry, inode);
1751                 unlock_new_inode(inode);
1752                 return 0;
1753         }
1754         drop_nlink(inode);
1755         unlock_new_inode(inode);
1756         iput(inode);
1757         return err;
1758 }
1759
1760 /*
1761  * By the time this is called, we already have created
1762  * the directory cache entry for the new file, but it
1763  * is so far negative - it has no inode.
1764  *
1765  * If the create succeeds, we fill in the inode information
1766  * with d_instantiate().
1767  */
1768 static int ext4_create(struct inode *dir, struct dentry *dentry, int mode,
1769                        struct nameidata *nd)
1770 {
1771         handle_t *handle;
1772         struct inode *inode;
1773         int err, retries = 0;
1774
1775 retry:
1776         handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
1777                                         EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3 +
1778                                         2*EXT4_QUOTA_INIT_BLOCKS(dir->i_sb));
1779         if (IS_ERR(handle))
1780                 return PTR_ERR(handle);
1781
1782         if (IS_DIRSYNC(dir))
1783                 ext4_handle_sync(handle);
1784
1785         inode = ext4_new_inode (handle, dir, mode);
1786         err = PTR_ERR(inode);
1787         if (!IS_ERR(inode)) {
1788                 inode->i_op = &ext4_file_inode_operations;
1789                 inode->i_fop = &ext4_file_operations;
1790                 ext4_set_aops(inode);
1791                 err = ext4_add_nondir(handle, dentry, inode);
1792         }
1793         ext4_journal_stop(handle);
1794         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
1795                 goto retry;
1796         return err;
1797 }
1798
1799 static int ext4_mknod(struct inode *dir, struct dentry *dentry,
1800                       int mode, dev_t rdev)
1801 {
1802         handle_t *handle;
1803         struct inode *inode;
1804         int err, retries = 0;
1805
1806         if (!new_valid_dev(rdev))
1807                 return -EINVAL;
1808
1809 retry:
1810         handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
1811                                         EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3 +
1812                                         2*EXT4_QUOTA_INIT_BLOCKS(dir->i_sb));
1813         if (IS_ERR(handle))
1814                 return PTR_ERR(handle);
1815
1816         if (IS_DIRSYNC(dir))
1817                 ext4_handle_sync(handle);
1818
1819         inode = ext4_new_inode(handle, dir, mode);
1820         err = PTR_ERR(inode);
1821         if (!IS_ERR(inode)) {
1822                 init_special_inode(inode, inode->i_mode, rdev);
1823 #ifdef CONFIG_EXT4_FS_XATTR
1824                 inode->i_op = &ext4_special_inode_operations;
1825 #endif
1826                 err = ext4_add_nondir(handle, dentry, inode);
1827         }
1828         ext4_journal_stop(handle);
1829         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
1830                 goto retry;
1831         return err;
1832 }
1833
1834 static int ext4_mkdir(struct inode *dir, struct dentry *dentry, int mode)
1835 {
1836         handle_t *handle;
1837         struct inode *inode;
1838         struct buffer_head *dir_block;
1839         struct ext4_dir_entry_2 *de;
1840         unsigned int blocksize = dir->i_sb->s_blocksize;
1841         int err, retries = 0;
1842
1843         if (EXT4_DIR_LINK_MAX(dir))
1844                 return -EMLINK;
1845
1846 retry:
1847         handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
1848                                         EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3 +
1849                                         2*EXT4_QUOTA_INIT_BLOCKS(dir->i_sb));
1850         if (IS_ERR(handle))
1851                 return PTR_ERR(handle);
1852
1853         if (IS_DIRSYNC(dir))
1854                 ext4_handle_sync(handle);
1855
1856         inode = ext4_new_inode(handle, dir, S_IFDIR | mode);
1857         err = PTR_ERR(inode);
1858         if (IS_ERR(inode))
1859                 goto out_stop;
1860
1861         inode->i_op = &ext4_dir_inode_operations;
1862         inode->i_fop = &ext4_dir_operations;
1863         inode->i_size = EXT4_I(inode)->i_disksize = inode->i_sb->s_blocksize;
1864         dir_block = ext4_bread(handle, inode, 0, 1, &err);
1865         if (!dir_block)
1866                 goto out_clear_inode;
1867         BUFFER_TRACE(dir_block, "get_write_access");
1868         ext4_journal_get_write_access(handle, dir_block);
1869         de = (struct ext4_dir_entry_2 *) dir_block->b_data;
1870         de->inode = cpu_to_le32(inode->i_ino);
1871         de->name_len = 1;
1872         de->rec_len = ext4_rec_len_to_disk(EXT4_DIR_REC_LEN(de->name_len),
1873                                            blocksize);
1874         strcpy(de->name, ".");
1875         ext4_set_de_type(dir->i_sb, de, S_IFDIR);
1876         de = ext4_next_entry(de, blocksize);
1877         de->inode = cpu_to_le32(dir->i_ino);
1878         de->rec_len = ext4_rec_len_to_disk(blocksize - EXT4_DIR_REC_LEN(1),
1879                                            blocksize);
1880         de->name_len = 2;
1881         strcpy(de->name, "..");
1882         ext4_set_de_type(dir->i_sb, de, S_IFDIR);
1883         inode->i_nlink = 2;
1884         BUFFER_TRACE(dir_block, "call ext4_handle_dirty_metadata");
1885         ext4_handle_dirty_metadata(handle, dir, dir_block);
1886         brelse(dir_block);
1887         ext4_mark_inode_dirty(handle, inode);
1888         err = ext4_add_entry(handle, dentry, inode);
1889         if (err) {
1890 out_clear_inode:
1891                 clear_nlink(inode);
1892                 unlock_new_inode(inode);
1893                 ext4_mark_inode_dirty(handle, inode);
1894                 iput(inode);
1895                 goto out_stop;
1896         }
1897         ext4_inc_count(handle, dir);
1898         ext4_update_dx_flag(dir);
1899         ext4_mark_inode_dirty(handle, dir);
1900         d_instantiate(dentry, inode);
1901         unlock_new_inode(inode);
1902 out_stop:
1903         ext4_journal_stop(handle);
1904         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
1905                 goto retry;
1906         return err;
1907 }
1908
1909 /*
1910  * routine to check that the specified directory is empty (for rmdir)
1911  */
1912 static int empty_dir(struct inode *inode)
1913 {
1914         unsigned int offset;
1915         struct buffer_head *bh;
1916         struct ext4_dir_entry_2 *de, *de1;
1917         struct super_block *sb;
1918         int err = 0;
1919
1920         sb = inode->i_sb;
1921         if (inode->i_size < EXT4_DIR_REC_LEN(1) + EXT4_DIR_REC_LEN(2) ||
1922             !(bh = ext4_bread(NULL, inode, 0, 0, &err))) {
1923                 if (err)
1924                         ext4_error(inode->i_sb, __func__,
1925                                    "error %d reading directory #%lu offset 0",
1926                                    err, inode->i_ino);
1927                 else
1928                         ext4_warning(inode->i_sb, __func__,
1929                                      "bad directory (dir #%lu) - no data block",
1930                                      inode->i_ino);
1931                 return 1;
1932         }
1933         de = (struct ext4_dir_entry_2 *) bh->b_data;
1934         de1 = ext4_next_entry(de, sb->s_blocksize);
1935         if (le32_to_cpu(de->inode) != inode->i_ino ||
1936                         !le32_to_cpu(de1->inode) ||
1937                         strcmp(".", de->name) ||
1938                         strcmp("..", de1->name)) {
1939                 ext4_warning(inode->i_sb, "empty_dir",
1940                              "bad directory (dir #%lu) - no `.' or `..'",
1941                              inode->i_ino);
1942                 brelse(bh);
1943                 return 1;
1944         }
1945         offset = ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize) +
1946                  ext4_rec_len_from_disk(de1->rec_len, sb->s_blocksize);
1947         de = ext4_next_entry(de1, sb->s_blocksize);
1948         while (offset < inode->i_size) {
1949                 if (!bh ||
1950                         (void *) de >= (void *) (bh->b_data+sb->s_blocksize)) {
1951                         err = 0;
1952                         brelse(bh);
1953                         bh = ext4_bread(NULL, inode,
1954                                 offset >> EXT4_BLOCK_SIZE_BITS(sb), 0, &err);
1955                         if (!bh) {
1956                                 if (err)
1957                                         ext4_error(sb, __func__,
1958                                                    "error %d reading directory"
1959                                                    " #%lu offset %u",
1960                                                    err, inode->i_ino, offset);
1961                                 offset += sb->s_blocksize;
1962                                 continue;
1963                         }
1964                         de = (struct ext4_dir_entry_2 *) bh->b_data;
1965                 }
1966                 if (!ext4_check_dir_entry("empty_dir", inode, de, bh, offset)) {
1967                         de = (struct ext4_dir_entry_2 *)(bh->b_data +
1968                                                          sb->s_blocksize);
1969                         offset = (offset | (sb->s_blocksize - 1)) + 1;
1970                         continue;
1971                 }
1972                 if (le32_to_cpu(de->inode)) {
1973                         brelse(bh);
1974                         return 0;
1975                 }
1976                 offset += ext4_rec_len_from_disk(de->rec_len, sb->s_blocksize);
1977                 de = ext4_next_entry(de, sb->s_blocksize);
1978         }
1979         brelse(bh);
1980         return 1;
1981 }
1982
1983 /* ext4_orphan_add() links an unlinked or truncated inode into a list of
1984  * such inodes, starting at the superblock, in case we crash before the
1985  * file is closed/deleted, or in case the inode truncate spans multiple
1986  * transactions and the last transaction is not recovered after a crash.
1987  *
1988  * At filesystem recovery time, we walk this list deleting unlinked
1989  * inodes and truncating linked inodes in ext4_orphan_cleanup().
1990  */
1991 int ext4_orphan_add(handle_t *handle, struct inode *inode)
1992 {
1993         struct super_block *sb = inode->i_sb;
1994         struct ext4_iloc iloc;
1995         int err = 0, rc;
1996
1997         if (!ext4_handle_valid(handle))
1998                 return 0;
1999
2000         lock_super(sb);
2001         if (!list_empty(&EXT4_I(inode)->i_orphan))
2002                 goto out_unlock;
2003
2004         /* Orphan handling is only valid for files with data blocks
2005          * being truncated, or files being unlinked. */
2006
2007         /* @@@ FIXME: Observation from aviro:
2008          * I think I can trigger J_ASSERT in ext4_orphan_add().  We block
2009          * here (on lock_super()), so race with ext4_link() which might bump
2010          * ->i_nlink. For, say it, character device. Not a regular file,
2011          * not a directory, not a symlink and ->i_nlink > 0.
2012          */
2013         J_ASSERT((S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
2014                   S_ISLNK(inode->i_mode)) || inode->i_nlink == 0);
2015
2016         BUFFER_TRACE(EXT4_SB(sb)->s_sbh, "get_write_access");
2017         err = ext4_journal_get_write_access(handle, EXT4_SB(sb)->s_sbh);
2018         if (err)
2019                 goto out_unlock;
2020
2021         err = ext4_reserve_inode_write(handle, inode, &iloc);
2022         if (err)
2023                 goto out_unlock;
2024
2025         /* Insert this inode at the head of the on-disk orphan list... */
2026         NEXT_ORPHAN(inode) = le32_to_cpu(EXT4_SB(sb)->s_es->s_last_orphan);
2027         EXT4_SB(sb)->s_es->s_last_orphan = cpu_to_le32(inode->i_ino);
2028         err = ext4_handle_dirty_metadata(handle, inode, EXT4_SB(sb)->s_sbh);
2029         rc = ext4_mark_iloc_dirty(handle, inode, &iloc);
2030         if (!err)
2031                 err = rc;
2032
2033         /* Only add to the head of the in-memory list if all the
2034          * previous operations succeeded.  If the orphan_add is going to
2035          * fail (possibly taking the journal offline), we can't risk
2036          * leaving the inode on the orphan list: stray orphan-list
2037          * entries can cause panics at unmount time.
2038          *
2039          * This is safe: on error we're going to ignore the orphan list
2040          * anyway on the next recovery. */
2041         if (!err)
2042                 list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2043
2044         jbd_debug(4, "superblock will point to %lu\n", inode->i_ino);
2045         jbd_debug(4, "orphan inode %lu will point to %d\n",
2046                         inode->i_ino, NEXT_ORPHAN(inode));
2047 out_unlock:
2048         unlock_super(sb);
2049         ext4_std_error(inode->i_sb, err);
2050         return err;
2051 }
2052
2053 /*
2054  * ext4_orphan_del() removes an unlinked or truncated inode from the list
2055  * of such inodes stored on disk, because it is finally being cleaned up.
2056  */
2057 int ext4_orphan_del(handle_t *handle, struct inode *inode)
2058 {
2059         struct list_head *prev;
2060         struct ext4_inode_info *ei = EXT4_I(inode);
2061         struct ext4_sb_info *sbi;
2062         __u32 ino_next;
2063         struct ext4_iloc iloc;
2064         int err = 0;
2065
2066         if (!ext4_handle_valid(handle))
2067                 return 0;
2068
2069         lock_super(inode->i_sb);
2070         if (list_empty(&ei->i_orphan)) {
2071                 unlock_super(inode->i_sb);
2072                 return 0;
2073         }
2074
2075         ino_next = NEXT_ORPHAN(inode);
2076         prev = ei->i_orphan.prev;
2077         sbi = EXT4_SB(inode->i_sb);
2078
2079         jbd_debug(4, "remove inode %lu from orphan list\n", inode->i_ino);
2080
2081         list_del_init(&ei->i_orphan);
2082
2083         /* If we're on an error path, we may not have a valid
2084          * transaction handle with which to update the orphan list on
2085          * disk, but we still need to remove the inode from the linked
2086          * list in memory. */
2087         if (sbi->s_journal && !handle)
2088                 goto out;
2089
2090         err = ext4_reserve_inode_write(handle, inode, &iloc);
2091         if (err)
2092                 goto out_err;
2093
2094         if (prev == &sbi->s_orphan) {
2095                 jbd_debug(4, "superblock will point to %u\n", ino_next);
2096                 BUFFER_TRACE(sbi->s_sbh, "get_write_access");
2097                 err = ext4_journal_get_write_access(handle, sbi->s_sbh);
2098                 if (err)
2099                         goto out_brelse;
2100                 sbi->s_es->s_last_orphan = cpu_to_le32(ino_next);
2101                 err = ext4_handle_dirty_metadata(handle, inode, sbi->s_sbh);
2102         } else {
2103                 struct ext4_iloc iloc2;
2104                 struct inode *i_prev =
2105                         &list_entry(prev, struct ext4_inode_info, i_orphan)->vfs_inode;
2106
2107                 jbd_debug(4, "orphan inode %lu will point to %u\n",
2108                           i_prev->i_ino, ino_next);
2109                 err = ext4_reserve_inode_write(handle, i_prev, &iloc2);
2110                 if (err)
2111                         goto out_brelse;
2112                 NEXT_ORPHAN(i_prev) = ino_next;
2113                 err = ext4_mark_iloc_dirty(handle, i_prev, &iloc2);
2114         }
2115         if (err)
2116                 goto out_brelse;
2117         NEXT_ORPHAN(inode) = 0;
2118         err = ext4_mark_iloc_dirty(handle, inode, &iloc);
2119
2120 out_err:
2121         ext4_std_error(inode->i_sb, err);
2122 out:
2123         unlock_super(inode->i_sb);
2124         return err;
2125
2126 out_brelse:
2127         brelse(iloc.bh);
2128         goto out_err;
2129 }
2130
2131 static int ext4_rmdir(struct inode *dir, struct dentry *dentry)
2132 {
2133         int retval;
2134         struct inode *inode;
2135         struct buffer_head *bh;
2136         struct ext4_dir_entry_2 *de;
2137         handle_t *handle;
2138
2139         /* Initialize quotas before so that eventual writes go in
2140          * separate transaction */
2141         vfs_dq_init(dentry->d_inode);
2142         handle = ext4_journal_start(dir, EXT4_DELETE_TRANS_BLOCKS(dir->i_sb));
2143         if (IS_ERR(handle))
2144                 return PTR_ERR(handle);
2145
2146         retval = -ENOENT;
2147         bh = ext4_find_entry(dir, &dentry->d_name, &de);
2148         if (!bh)
2149                 goto end_rmdir;
2150
2151         if (IS_DIRSYNC(dir))
2152                 ext4_handle_sync(handle);
2153
2154         inode = dentry->d_inode;
2155
2156         retval = -EIO;
2157         if (le32_to_cpu(de->inode) != inode->i_ino)
2158                 goto end_rmdir;
2159
2160         retval = -ENOTEMPTY;
2161         if (!empty_dir(inode))
2162                 goto end_rmdir;
2163
2164         retval = ext4_delete_entry(handle, dir, de, bh);
2165         if (retval)
2166                 goto end_rmdir;
2167         if (!EXT4_DIR_LINK_EMPTY(inode))
2168                 ext4_warning(inode->i_sb, "ext4_rmdir",
2169                              "empty directory has too many links (%d)",
2170                              inode->i_nlink);
2171         inode->i_version++;
2172         clear_nlink(inode);
2173         /* There's no need to set i_disksize: the fact that i_nlink is
2174          * zero will ensure that the right thing happens during any
2175          * recovery. */
2176         inode->i_size = 0;
2177         ext4_orphan_add(handle, inode);
2178         inode->i_ctime = dir->i_ctime = dir->i_mtime = ext4_current_time(inode);
2179         ext4_mark_inode_dirty(handle, inode);
2180         ext4_dec_count(handle, dir);
2181         ext4_update_dx_flag(dir);
2182         ext4_mark_inode_dirty(handle, dir);
2183
2184 end_rmdir:
2185         ext4_journal_stop(handle);
2186         brelse(bh);
2187         return retval;
2188 }
2189
2190 static int ext4_unlink(struct inode *dir, struct dentry *dentry)
2191 {
2192         int retval;
2193         struct inode *inode;
2194         struct buffer_head *bh;
2195         struct ext4_dir_entry_2 *de;
2196         handle_t *handle;
2197
2198         /* Initialize quotas before so that eventual writes go
2199          * in separate transaction */
2200         vfs_dq_init(dentry->d_inode);
2201         handle = ext4_journal_start(dir, EXT4_DELETE_TRANS_BLOCKS(dir->i_sb));
2202         if (IS_ERR(handle))
2203                 return PTR_ERR(handle);
2204
2205         if (IS_DIRSYNC(dir))
2206                 ext4_handle_sync(handle);
2207
2208         retval = -ENOENT;
2209         bh = ext4_find_entry(dir, &dentry->d_name, &de);
2210         if (!bh)
2211                 goto end_unlink;
2212
2213         inode = dentry->d_inode;
2214
2215         retval = -EIO;
2216         if (le32_to_cpu(de->inode) != inode->i_ino)
2217                 goto end_unlink;
2218
2219         if (!inode->i_nlink) {
2220                 ext4_warning(inode->i_sb, "ext4_unlink",
2221                              "Deleting nonexistent file (%lu), %d",
2222                              inode->i_ino, inode->i_nlink);
2223                 inode->i_nlink = 1;
2224         }
2225         retval = ext4_delete_entry(handle, dir, de, bh);
2226         if (retval)
2227                 goto end_unlink;
2228         dir->i_ctime = dir->i_mtime = ext4_current_time(dir);
2229         ext4_update_dx_flag(dir);
2230         ext4_mark_inode_dirty(handle, dir);
2231         drop_nlink(inode);
2232         if (!inode->i_nlink)
2233                 ext4_orphan_add(handle, inode);
2234         inode->i_ctime = ext4_current_time(inode);
2235         ext4_mark_inode_dirty(handle, inode);
2236         retval = 0;
2237
2238 end_unlink:
2239         ext4_journal_stop(handle);
2240         brelse(bh);
2241         return retval;
2242 }
2243
2244 static int ext4_symlink(struct inode *dir,
2245                         struct dentry *dentry, const char *symname)
2246 {
2247         handle_t *handle;
2248         struct inode *inode;
2249         int l, err, retries = 0;
2250
2251         l = strlen(symname)+1;
2252         if (l > dir->i_sb->s_blocksize)
2253                 return -ENAMETOOLONG;
2254
2255 retry:
2256         handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2257                                         EXT4_INDEX_EXTRA_TRANS_BLOCKS + 5 +
2258                                         2*EXT4_QUOTA_INIT_BLOCKS(dir->i_sb));
2259         if (IS_ERR(handle))
2260                 return PTR_ERR(handle);
2261
2262         if (IS_DIRSYNC(dir))
2263                 ext4_handle_sync(handle);
2264
2265         inode = ext4_new_inode(handle, dir, S_IFLNK|S_IRWXUGO);
2266         err = PTR_ERR(inode);
2267         if (IS_ERR(inode))
2268                 goto out_stop;
2269
2270         if (l > sizeof(EXT4_I(inode)->i_data)) {
2271                 inode->i_op = &ext4_symlink_inode_operations;
2272                 ext4_set_aops(inode);
2273                 /*
2274                  * page_symlink() calls into ext4_prepare/commit_write.
2275                  * We have a transaction open.  All is sweetness.  It also sets
2276                  * i_size in generic_commit_write().
2277                  */
2278                 err = __page_symlink(inode, symname, l, 1);
2279                 if (err) {
2280                         clear_nlink(inode);
2281                         unlock_new_inode(inode);
2282                         ext4_mark_inode_dirty(handle, inode);
2283                         iput(inode);
2284                         goto out_stop;
2285                 }
2286         } else {
2287                 /* clear the extent format for fast symlink */
2288                 EXT4_I(inode)->i_flags &= ~EXT4_EXTENTS_FL;
2289                 inode->i_op = &ext4_fast_symlink_inode_operations;
2290                 memcpy((char *)&EXT4_I(inode)->i_data, symname, l);
2291                 inode->i_size = l-1;
2292         }
2293         EXT4_I(inode)->i_disksize = inode->i_size;
2294         err = ext4_add_nondir(handle, dentry, inode);
2295 out_stop:
2296         ext4_journal_stop(handle);
2297         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2298                 goto retry;
2299         return err;
2300 }
2301
2302 static int ext4_link(struct dentry *old_dentry,
2303                      struct inode *dir, struct dentry *dentry)
2304 {
2305         handle_t *handle;
2306         struct inode *inode = old_dentry->d_inode;
2307         int err, retries = 0;
2308
2309         if (EXT4_DIR_LINK_MAX(inode))
2310                 return -EMLINK;
2311
2312         /*
2313          * Return -ENOENT if we've raced with unlink and i_nlink is 0.  Doing
2314          * otherwise has the potential to corrupt the orphan inode list.
2315          */
2316         if (inode->i_nlink == 0)
2317                 return -ENOENT;
2318
2319 retry:
2320         handle = ext4_journal_start(dir, EXT4_DATA_TRANS_BLOCKS(dir->i_sb) +
2321                                         EXT4_INDEX_EXTRA_TRANS_BLOCKS);
2322         if (IS_ERR(handle))
2323                 return PTR_ERR(handle);
2324
2325         if (IS_DIRSYNC(dir))
2326                 ext4_handle_sync(handle);
2327
2328         inode->i_ctime = ext4_current_time(inode);
2329         ext4_inc_count(handle, inode);
2330         atomic_inc(&inode->i_count);
2331
2332         err = ext4_add_entry(handle, dentry, inode);
2333         if (!err) {
2334                 ext4_mark_inode_dirty(handle, inode);
2335                 d_instantiate(dentry, inode);
2336         } else {
2337                 drop_nlink(inode);
2338                 iput(inode);
2339         }
2340         ext4_journal_stop(handle);
2341         if (err == -ENOSPC && ext4_should_retry_alloc(dir->i_sb, &retries))
2342                 goto retry;
2343         return err;
2344 }
2345
2346 #define PARENT_INO(buffer, size) \
2347         (ext4_next_entry((struct ext4_dir_entry_2 *)(buffer), size)->inode)
2348
2349 /*
2350  * Anybody can rename anything with this: the permission checks are left to the
2351  * higher-level routines.
2352  */
2353 static int ext4_rename(struct inode *old_dir, struct dentry *old_dentry,
2354                        struct inode *new_dir, struct dentry *new_dentry)
2355 {
2356         handle_t *handle;
2357         struct inode *old_inode, *new_inode;
2358         struct buffer_head *old_bh, *new_bh, *dir_bh;
2359         struct ext4_dir_entry_2 *old_de, *new_de;
2360         int retval, force_da_alloc = 0;
2361
2362         old_bh = new_bh = dir_bh = NULL;
2363
2364         /* Initialize quotas before so that eventual writes go
2365          * in separate transaction */
2366         if (new_dentry->d_inode)
2367                 vfs_dq_init(new_dentry->d_inode);
2368         handle = ext4_journal_start(old_dir, 2 *
2369                                         EXT4_DATA_TRANS_BLOCKS(old_dir->i_sb) +
2370                                         EXT4_INDEX_EXTRA_TRANS_BLOCKS + 2);
2371         if (IS_ERR(handle))
2372                 return PTR_ERR(handle);
2373
2374         if (IS_DIRSYNC(old_dir) || IS_DIRSYNC(new_dir))
2375                 ext4_handle_sync(handle);
2376
2377         old_bh = ext4_find_entry(old_dir, &old_dentry->d_name, &old_de);
2378         /*
2379          *  Check for inode number is _not_ due to possible IO errors.
2380          *  We might rmdir the source, keep it as pwd of some process
2381          *  and merrily kill the link to whatever was created under the
2382          *  same name. Goodbye sticky bit ;-<
2383          */
2384         old_inode = old_dentry->d_inode;
2385         retval = -ENOENT;
2386         if (!old_bh || le32_to_cpu(old_de->inode) != old_inode->i_ino)
2387                 goto end_rename;
2388
2389         new_inode = new_dentry->d_inode;
2390         new_bh = ext4_find_entry(new_dir, &new_dentry->d_name, &new_de);
2391         if (new_bh) {
2392                 if (!new_inode) {
2393                         brelse(new_bh);
2394                         new_bh = NULL;
2395                 }
2396         }
2397         if (S_ISDIR(old_inode->i_mode)) {
2398                 if (new_inode) {
2399                         retval = -ENOTEMPTY;
2400                         if (!empty_dir(new_inode))
2401                                 goto end_rename;
2402                 }
2403                 retval = -EIO;
2404                 dir_bh = ext4_bread(handle, old_inode, 0, 0, &retval);
2405                 if (!dir_bh)
2406                         goto end_rename;
2407                 if (le32_to_cpu(PARENT_INO(dir_bh->b_data,
2408                                 old_dir->i_sb->s_blocksize)) != old_dir->i_ino)
2409                         goto end_rename;
2410                 retval = -EMLINK;
2411                 if (!new_inode && new_dir != old_dir &&
2412                                 new_dir->i_nlink >= EXT4_LINK_MAX)
2413                         goto end_rename;
2414         }
2415         if (!new_bh) {
2416                 retval = ext4_add_entry(handle, new_dentry, old_inode);
2417                 if (retval)
2418                         goto end_rename;
2419         } else {
2420                 BUFFER_TRACE(new_bh, "get write access");
2421                 ext4_journal_get_write_access(handle, new_bh);
2422                 new_de->inode = cpu_to_le32(old_inode->i_ino);
2423                 if (EXT4_HAS_INCOMPAT_FEATURE(new_dir->i_sb,
2424                                               EXT4_FEATURE_INCOMPAT_FILETYPE))
2425                         new_de->file_type = old_de->file_type;
2426                 new_dir->i_version++;
2427                 new_dir->i_ctime = new_dir->i_mtime =
2428                                         ext4_current_time(new_dir);
2429                 ext4_mark_inode_dirty(handle, new_dir);
2430                 BUFFER_TRACE(new_bh, "call ext4_handle_dirty_metadata");
2431                 ext4_handle_dirty_metadata(handle, new_dir, new_bh);
2432                 brelse(new_bh);
2433                 new_bh = NULL;
2434         }
2435
2436         /*
2437          * Like most other Unix systems, set the ctime for inodes on a
2438          * rename.
2439          */
2440         old_inode->i_ctime = ext4_current_time(old_inode);
2441         ext4_mark_inode_dirty(handle, old_inode);
2442
2443         /*
2444          * ok, that's it
2445          */
2446         if (le32_to_cpu(old_de->inode) != old_inode->i_ino ||
2447             old_de->name_len != old_dentry->d_name.len ||
2448             strncmp(old_de->name, old_dentry->d_name.name, old_de->name_len) ||
2449             (retval = ext4_delete_entry(handle, old_dir,
2450                                         old_de, old_bh)) == -ENOENT) {
2451                 /* old_de could have moved from under us during htree split, so
2452                  * make sure that we are deleting the right entry.  We might
2453                  * also be pointing to a stale entry in the unused part of
2454                  * old_bh so just checking inum and the name isn't enough. */
2455                 struct buffer_head *old_bh2;
2456                 struct ext4_dir_entry_2 *old_de2;
2457
2458                 old_bh2 = ext4_find_entry(old_dir, &old_dentry->d_name, &old_de2);
2459                 if (old_bh2) {
2460                         retval = ext4_delete_entry(handle, old_dir,
2461                                                    old_de2, old_bh2);
2462                         brelse(old_bh2);
2463                 }
2464         }
2465         if (retval) {
2466                 ext4_warning(old_dir->i_sb, "ext4_rename",
2467                                 "Deleting old file (%lu), %d, error=%d",
2468                                 old_dir->i_ino, old_dir->i_nlink, retval);
2469         }
2470
2471         if (new_inode) {
2472                 ext4_dec_count(handle, new_inode);
2473                 new_inode->i_ctime = ext4_current_time(new_inode);
2474         }
2475         old_dir->i_ctime = old_dir->i_mtime = ext4_current_time(old_dir);
2476         ext4_update_dx_flag(old_dir);
2477         if (dir_bh) {
2478                 BUFFER_TRACE(dir_bh, "get_write_access");
2479                 ext4_journal_get_write_access(handle, dir_bh);
2480                 PARENT_INO(dir_bh->b_data, new_dir->i_sb->s_blocksize) =
2481                                                 cpu_to_le32(new_dir->i_ino);
2482                 BUFFER_TRACE(dir_bh, "call ext4_handle_dirty_metadata");
2483                 ext4_handle_dirty_metadata(handle, old_dir, dir_bh);
2484                 ext4_dec_count(handle, old_dir);
2485                 if (new_inode) {
2486                         /* checked empty_dir above, can't have another parent,
2487                          * ext4_dec_count() won't work for many-linked dirs */
2488                         new_inode->i_nlink = 0;
2489                 } else {
2490                         ext4_inc_count(handle, new_dir);
2491                         ext4_update_dx_flag(new_dir);
2492                         ext4_mark_inode_dirty(handle, new_dir);
2493                 }
2494         }
2495         ext4_mark_inode_dirty(handle, old_dir);
2496         if (new_inode) {
2497                 ext4_mark_inode_dirty(handle, new_inode);
2498                 if (!new_inode->i_nlink)
2499                         ext4_orphan_add(handle, new_inode);
2500                 if (!test_opt(new_dir->i_sb, NO_AUTO_DA_ALLOC))
2501                         force_da_alloc = 1;
2502         }
2503         retval = 0;
2504
2505 end_rename:
2506         brelse(dir_bh);
2507         brelse(old_bh);
2508         brelse(new_bh);
2509         ext4_journal_stop(handle);
2510         if (retval == 0 && force_da_alloc)
2511                 ext4_alloc_da_blocks(old_inode);
2512         return retval;
2513 }
2514
2515 /*
2516  * directories can handle most operations...
2517  */
2518 const struct inode_operations ext4_dir_inode_operations = {
2519         .create         = ext4_create,
2520         .lookup         = ext4_lookup,
2521         .link           = ext4_link,
2522         .unlink         = ext4_unlink,
2523         .symlink        = ext4_symlink,
2524         .mkdir          = ext4_mkdir,
2525         .rmdir          = ext4_rmdir,
2526         .mknod          = ext4_mknod,
2527         .rename         = ext4_rename,
2528         .setattr        = ext4_setattr,
2529 #ifdef CONFIG_EXT4_FS_XATTR
2530         .setxattr       = generic_setxattr,
2531         .getxattr       = generic_getxattr,
2532         .listxattr      = ext4_listxattr,
2533         .removexattr    = generic_removexattr,
2534 #endif
2535         .permission     = ext4_permission,
2536 };
2537
2538 const struct inode_operations ext4_special_inode_operations = {
2539         .setattr        = ext4_setattr,
2540 #ifdef CONFIG_EXT4_FS_XATTR
2541         .setxattr       = generic_setxattr,
2542         .getxattr       = generic_getxattr,
2543         .listxattr      = ext4_listxattr,
2544         .removexattr    = generic_removexattr,
2545 #endif
2546         .permission     = ext4_permission,
2547 };